On a cobbled street, a man in designer wellingtons was grooming a dappled pony outside the private stables of his historic mansion. A Bentley rolled past the picturesque village green. Liveried staff in waistcoats passed through the high, electric gates of a manor house and visitors politely admired amateur watercolours in an art show in what is held to be the richest village in France.

Quaint, discreet, and perfectly manicured, Marnes-la-Coquette has 1,700 residents, including scores of millionaires, who voted staunchly for the rightwing president Nicolas Sarkozy in the last presidential election. Surrounded by parkland, the village nudges the leafy suburbs west of Paris favoured by bankers, ageing pop stars and aristocratic families dubbed "the heirs". Already living behind high walls, these super-wealthy could soon have more reason than ever to retreat behind a parapet.

"There's a taboo about money and success in this country. One must be discreet about one's wealth," whispered a well-dressed grandmother, clutching her handbag.

Squeezing the rich, banker-bashing, and hammering the boss class have become focus points in a bruising French presidential election campaign. France, whether harking back to its revolution, or simply seething with rage at the injustices exposed by the financial crisis, now wants to lead the world in clobbering the mega-rich. Tax rises for the wealthy are at the heart of the debate and if the left wins, France could become the country with the highest tax on the rich in the EU, and one of the most punishing in the world.

The French public are resoundingly in favour of tightening the grip on the mega-wealthy. François Hollande, the Socialist frontrunner who polls say would win the second-round vote in May, has promised a 75% tax bracket on earnings after €1m. More than six out of 10 French people approve. Jean-Luc Mélenchon, the fire-brand leftist backed by the Communist party, has surged to third place in the polls with his promise to cap fat cat salaries at €360,000 (£300,000), after which income tax would be 100% and the state would "take it all".

Even Sarkozy, known as "president of the rich" for his generous tax breaks to the wealthy, has restyled himself as "president of the people", offering to cut tax loopholes and make French tax exiles who flee abroad pay back the difference to the French state.

The French people are more distrustful of capitalism than the Chinese, polls show. Two-thirds agree with the concept that the state should take from the rich to give to the poor. But many question whether the election rhetoric will succeed in rooting out a deeply unfair French system where the super-rich often manage to pay barely any tax at all, conducting startling tax dodges by hiring top accountants to pick through the myriad legal loopholes in their favour.

France is still seething at the L'Oreal cosmetics heiress, Liliane Bettencourt, France's richest woman, who lives in a mansion lined with Matisse paintings where her pet dogs eat only fresh fish, yet who got a €30m tax rebate from the state a few years back. A judge is investigating whether her household gave brown envelopes of cash to Sarkozy's party for illegal election campaign funding in 2007.

Hollande, who once famously announced "I don't like the rich" said making the wealthy paying more tax was "patriotism". Forced to admit that the 75% tax on people who earn over €1m would affect only a few thousand people and not bring in great amounts to state coffers, he said: "It's not a question of return, it's a question of morality." High tax would deter businesses from handing out fat-cat salaries, he argued.

The left would love to restyle France as a world champion against the greed and ravages of the Anglo-American system of brutal finance, but the French banking lobby remains strong. When Maurice Levy, the head of Publicis, the world's third biggest advertising agency, got a €16.2m bonus last month, the Socialists said it was "obscene". But the right attacked Hollande's proposed tax on the super-rich as barmy, saying it would make footballers flee and the boss-class pack its suitcases for Switzerland, Belgium or the UK. "There would be no Steve Jobs in France," warned Xavier Bertrand, the minister for work and employment.

The financial daily Les Echos illustrated a report on whether there would be a rich exodus from France with pictures of South Kensington and a Learjet on a runway. David Cameron has not only reduced the UK's top tax bracket while French candidates threaten to raise it, he has announced that fleeing French bankers are welcome in the City.

"I can't see an exodus – those who wanted to go have already long gone. Friends of ours have upped sticks to Switzerland," said a millionaire retired banker in suede jacket and checked shirt in Marnes-la-Coquette.

He already paid "wealth tax" on his property and capital, a longstanding French tax that is unique in the EU, and which Hollande wants to increase. "The fear is that all this election talk will stop people becoming entrepreneurs. In France, it's not seen as good to be rich, success is scorned. People are against the boss-class, but if you kill business leaders, there won't be any jobs."

The public mood of nausea towards the super-rich has made presidential candidates adapt their personal style. Sarkozy, dubbed "President Bling Bling" for his huge wristwatches and taste for holidaying with billionaires, made no excuses for giving himself a personal salary increase of more than 170% to €19,000 a month when he took office. Now he has been forced to publicly apologise for celebrating his 2007 election win in a flashy Champs Elysées restaurant and on a business mogul's yacht, blaming his ex-wife Cécilia. She, through her new husband, has angrily shot back that she had nothing to do with it. Meanwhile, Carla Bruni-Sarkozy, the multimillionaire heiress and ex-supermodel, who at the height of her fame made $7.5m a year, argued that she and Sarkozy were "modest" folk.

"At dinner parties, friends from both left and right agree that the top pay for some has become indecent, cut off from reality," said a wealthy, retired senior figure from a French car giant who lived in a village near Marnes-la-Coquette. "For years, the chasm between bosses' pay and workers' pay has been growing, I've seen it from the inside. I'm voting Hollande. I know I'll be personally affected, my taxes will rise, but there's a certain amount of sharing out and redistribution of wealth that just has to be done in this country."